window.cpp
78:SpecialMouseMode _special_mouse_mode; ///< Mode of the mouse.
1881:   if (_special_mouse_mode != WSM_PRESIZE) return;
1901:   if (_special_mouse_mode != WSM_DRAGDROP) return ES_NOT_HANDLED;

depot_gui.cpp
1042:   if (_special_mouse_mode != WSM_DRAGDROP) return;

group_gui.cpp
973:    if (_special_mouse_mode != WSM_DRAGDROP) return;

viewport.cpp
2823:   _special_mouse_mode = WSM_SIZING;
2853:   _special_mouse_mode = WSM_PRESIZE;
3431:   if (_special_mouse_mode != WSM_SIZING) return ES_NOT_HANDLED;
3448:   _special_mouse_mode = WSM_NONE;
3496:           _special_mouse_mode = WSM_DRAGDROP;
3498:           _special_mouse_mode = WSM_NONE;

window_gui.h
901:extern SpecialMouseMode _special_mouse_mode;